Various forms of semiconductor packages have been proposed in recent years as high performance and high function of electronic parts have been increased. In the manufacture of the semiconductor package, an adhesive is used in order to bond a semiconductor chip to a supporting member for mounting a semiconductor chip. Properties such as adhesion, thermocompression bondability, heat resistance, and humidity resistance are generally required of the adhesive, and attachment property is further required when the adhesive is used in a film form.
Adhesives with photosensitivity adequate to form a pattern in addition to the properties mentioned above may be required, depending on the functions, forms and methods for simplifying the assembly processes of the semiconductor packages. Photosensitivity is a function whereby portions irradiated with light are chemically altered to become insolubilized or solubilized in aqueous solutions or organic solvents. When a photosensitive adhesive exhibiting photosensitivity is used, it is exposed to light through a photomask and subjected to developing treatment, thus allowing a high definition adhesive pattern to be formed, and the formed adhesive pattern has thermocompression bondability to an adherend.
As photosensitive adhesive compositions, there are already known photoresists and polyimide resin precursor (polyamide acid)-based compositions (Patent Literatures 1 and 2 for example), and low-Tg polyimide resin-based compositions (Patent Literature 3). From the viewpoint of a work environment and an effluent treatment or the like, photosensitive adhesive compositions enabling pattern formation by an alkali developing solution are major.
In recent years, flip-chip mounting systems have attracted attention in the field of semiconductor packaging. In the flip-chip mounting systems, semiconductor chips are connected or a semiconductor chip and a supporting member for mounting a semiconductor chip are connected via a plurality of conductive bumps. In the flip-chip mounting system, by stress arising from the difference in thermal expansion coefficients of respective connecting members, connection defects between the base and semiconductor chip through the conductive bumps may be caused. Systems are known for sealing conductive bumps by filling a resin between the connecting members, in order to alleviate the stress (Patent Literature 4, for example).